@section Localised month and weekday names

All tools of the dateutils suite support @samp{--from-locale=LOC} to
globally declare that input with named specifiers uses names from LOC.

Tools that output absolute date/times also allow @samp{--locale=LOC} to
globally declare that output with named specifiers is to be expressed
using names from LOC.

Inspired by ISO 15897, we use the @samp{language_TERRITORY} notation for
@samp{LOC}, the encoding is always UTF-8 and hence the encoding part in
the @samp{LOC} notation is omitted.

To be independent of system support locales in dateutils are provided by
the @samp{locale} file (shipped), a simple tab separated text file:
following the locale identifier line (@samp{xx_XX}) is the line of
abbreviated weekday names (@samp{%a}) of which there must be 7
corresponding to Mon, Tue, ..., followed by long weekday names
(@samp{%A}), followed by abbreviated month names (@samp{%b}) of which
there must be 12 corresponding to Jan, Feb, ..., followed last by the
long month names (@samp{%B}).

The environment variable @samp{LOCALE_FILE} can be used to override the
default location.
